Pressure Regulator

More information on my set up. New Edelbrock 600 Carb, new Carter M6866 Advertised Max PSI 6.5.
Carb main is .095, Secondary is .089 and metering rod is a .068x.042 This is the leanest setting #27 in the book. IMS are at about 1 turn out. Engine runs fine, plenty of power for a 69 318 with Weiand Stealth, Elect ignition OEM Blue Box, timing is 14* BTDC. Switched to RN14YC plugs yesterday also, Long tube headers, Dual 2.5 exhaust no crossover. AFR in the Odd side collector. My Alternator and VR were dead, so I thought low power to the ignition was causing my problem. I replaced the Alt and VR, took several attempts but finally good Volts at all readings, and still is too rich. I live at 7000 ft and the engine will mostly be at that elevation.

Adjusting the IMS impacts the reading at idle no problem, but as soon as hit the throttle it goes rich and takes a while to return to a reasonable reading. If I set the idle AFR to be about 13-14, runs little rough on the idle. Then I hit the throttle it goes rich and the take about 15-30 seconds to return to 13-14 at idle.

So I am thinking fuel pressure is next to check. Also going smaller jets next.